Method and system for undersampled symbol synchronization

Abstract

Described is a system and method for providing a synchronization pattern in a communication system. The method includes generating a synchronization pattern with good randomness properties; packing a signal for transmission with m headers, each header consisting of the synchronization pattern 1/m symbol-time shifted from the previous header; and transmitting the signal. A further method provides for the sampling the transmitted signal with m headers of symbol-time shifted synchronization patterns; and determining symbol timing offset by computing and reordering correlation peaks from the synchronization patterns. A system includes a transmitting system, a receiving system, and a data channel. The transmitted signal includes m headers with 1/m symbol-time shifted synchronization patterns. The receiving system undersamples the transmitted signal with m synchronization patterns to simulate an oversampled synchronization pattern.

1. A method for providing symbol synchronization in a communications receiver, the method comprising;
 capture and sampling, by the receiver, a transmitted information signal comprising a plurality of synchronization patterns, wherein each synchronization pattern differs from the other synchronization patterns by a time shift; 
 generating a correlation peak from each of the plurality of synchronizations patterns; and 
 reordering the plurality of generated correlation peaks to provide a communications receiver symbol synchronization-offset pattern, whereby the receiver symbol synchronization-offset pattern simulates an oversampled synchronization pattern with improved signal to noise ratio over the sampling at a higher sampling rate. 
 
   
   
     2. The method of  claim 1 , wherein each of the m transmitted synchronization patterns differs by the other synchronization patterns by a multiple of 1/m of a symbol-time shift, wherein m is any positive, non-zero integer. 
   
   
     3. The method of  claim 1 , wherein the synchronization pattern is at least one of a random pattern, a pseudo random pattern, and a periodic function. 
   
   
     4. The method of  claim 3 , wherein the synchronization pattern further comprises a maximal-length sequence of length  15  generated by a 4-bit linear feedback shift register. 
   
   
     5. The method of  claim 1 , wherein generating a correlation peak for each of the m transmitted synchronization patterns further comprises generating substantially the same synchronization pattern such that a correlation peak is generated. 
   
   
     6. A method for symbol synchronization in a communication receiver, the method comprising the steps of:
 receiving, by the receiver, an encoded information signal, wherein the encoded signal includes an information signal and m headers, wherein m is a positive integer and each header comprising a synchronization pattern, wherein after the first synchronization pattern, each synchronization pattern is shifted by a fraction of a symbol-time from the other synchronization patterns; 
 sampling the encoded information signal; 
 generating a correlation peak for each of the m transmitted synchronization patterns; and 
 reordering the m generated correlation peaks to provide a symbol synchronization-offset pattern, whereby the symbol synchronization-offset pattern simulates an m times oversampled synchronization pattern with improved signal to noise ratio over the sampling at a m-time higher sampling rate. 
 
   
   
     7. The method of  claim 6 , wherein after the first synchronization pattern in the first header, each synchronization pattern is shifted by a multiple of 1/m of a symbol-time from the previous synchronization pattern. 
   
   
     8. The method of  claim 6 , wherein the synchronization pattern is a periodic sequence that is uniquely identifiable from the information signal. 
   
   
     9. The method of  claim 6 , wherein generating a correlation peak for each of the m transmitted synchronization patterns further comprises generating substantially the same synchronization pattern such that a correlation peak is generated. 
   
   
     10. A receiving system for providing a symbol synchronization-offset signal for use in a communications system, the receiving system comprising:
 a capture system arranged to receive and sample an information signal with a plurality of symbol synchronization patterns, wherein each of the plurality of synchronization patterns differ from the other synchronization patterns by a time shift; 
 a correlation generating system arranged to provide a correlation peak for each of the plurality of synchronization patterns; and 
 a symbol synchronization detecting system arranged to reorder the plurality of generated correlation peaks, such that a symbol synchronization-offset pattern is produced, whereby the symbol synchronization-offset pattern simulates an oversampled synchronization pattern with improved signal to noise ratio over true oversampled receiver samplings obtained by the sampling at a higher sampling rate. 
 
   
   
     11. The receiving system of  claim 10 , wherein the synchronization pattern is at least one of a random sequence, a pseudo random sequence, and a periodic sequence. 
   
   
     12. The receiving system of  claim 10 , wherein the synchronization pattern further comprises a maximal-length sequence of length  15  generated by a 4-bit linear feedback shift register. 
   
   
     13. The receiving system of  claim 10 , wherein the receiving system is implemented in a watch device.